Thinking of heading in the pure rogue path and this will cost me discipline.
I was told that Epic dodge is pretty good vs KD as it is generally made on the first attack.

I cant 100% recall but isent it possible to perform mutliple KD attempts in a round equal to the number of attacks you have?
If so Epic dodge might still work pretty well as the first attempt would have the highest AB.

You can make kd attempts for every attack so it ad you say: with a -4 ab to attempt kd you dodge the attempt most likely to hit. Still no protection from 20s etc.

Since there is literally no bonuses (except stuff like higher dc on nades and more skillpoints/ epic bonus feats) for rogue past lvl 24 I’d still consider a disc dump. But if you want pure class fun, go for it

Ive seen animal empathy used to great effect for characters that normally can't solo, but by high epics that will be a lot less relevant for you. As well, I wouldn't suggest the mindset that high AC renders discipline irrelevant. It just means that when they do hit you, you'll drop instantly and be exceedingly vulnerable.

Keep in mind, its not just knockdown you need to worry about. Called shot: leg from archers with excessively high AB and disarm attempts from characters with large weapons will screw you over equally, if not worse, than knockdown will. Epic dodge will let you dodge ONE attack per round, which will usually be the first attack. This helps, as that attack also has the highest AB, but it won't be enough if thats all you're relying on to keep you on your feet. Especially if you're playing a dex based build; most finessable weapons are disarm bait, called shot; leg will sap your DEX (ab and ac penalties) and knockdown will force you to loose all your dodge AC (average of 7 to 9 AC for epics)

Sidenote: You could do barbarian for your 6 full BAB class levels. The monk speed bonus doesn't stack with rogue speed buffs, but i'm not seeing anything about barbarian movement buffs being restricted. You'll get some small passive bonuses to damage as well if you have a decent CON score as well. If you have the skillpoints, taunt is also a very useful skill

Animal empathy is a fun skill, and there are some VERY powerful creatures you can EE, but if you have the skillpoints to dump into discipline and another skill, there are better options.